Pressurized water reactor dynamic simulation model

This thesis describes a fast running computer simulation model which enables analysis of various transients in a Pressurized Water Reactor in much faster-than-real-time. The model is capable of simulating anticipated transients, postulated accidents which do not disturb the system geometry and some operational transients. The modeling capabilities of this simulation program is expected to surpass those of published time-efficient codes. In spite of the added modeling capabilities, the new code is expected to be more time efficient than other existing simulation models. However, more tests are necessary in order to verify the capabilities and time efficiency of the code. A variety of numerical and physical approximations have been used in modeling the primary and secondary reactor systems. A numerical method is incorporated which calculates the characteristic times of the state variables representing the entire system and compares them with the present integration time step. A quasistatic approximation is applied to those state variables with rapid response, and a Runge-Kutta algorithm is applied to those with slow to moderate response. A simple-implicit scheme is used to solve the equations of motion. The equations for the nonequilibrium pressurizer model and the equations for the U-tube steam generator model are reduced analytically and solved implicitly. The features available in this simulation model provide a tool to study a variety of faults and multiple failures in the reactor system